1. Field of the Invention
The present invention relates to a vehicle behavior control apparatus that integrally controls vehicle behavior.
2. Description of the Related Art
Conventionally, a technique using a master-slave control method has been developed for integrally controlling vehicle behavior. The master-slave control method includes a master that transmits a control quantity of vehicle behavior and one or a plurality of slaves that controls actuators associated with the control quantity in accordance with the control quantity. The slaves operate in accordance with the request from the master.
The technique disclosed in Unexamined Japanese Patent Publication No. 2005-112007 also incorporates a master-slave control method. Unexamined Japanese Patent Publication No. 2005-112007 discloses an integrated control apparatus for a vehicle that controls actuators of a steering system, a brake system, and a drive system, in an optimally distributed condition according to the behavioral condition of the vehicle and the state of a road surface without use of the friction coefficient of the road surface, to thereby enhance vehicle stability.
Integrated controls of vehicle behavior using a conventional master-slave control method, such as the one disclosed in Unexamined Japanese Patent Publication No. 2005-112007, however, may cause to destabilize a vehicular running condition because a slave operates according to the request of a master. For example, when oversteer is generated as a vehicle behavior, wherein a vehicle is skidding toward an inner side of turning due to skidding of the rear wheels of the turning vehicle, a slave autonomously controls, for example, to brake the outer front wheel to eliminate oversteer, however, the master may request, to the slave, a control that increases the oversteer in consideration of the balance between the control of the slave and controls of the other slaves. In this case, the slave operates according to the request of the master and causes to destabilize vehicular running condition without eliminating the oversteer. Similarly, when understeer is generated, wherein a vehicle is skidding toward an outer side of turning due to skidding of the front wheels of the turning vehicle, the slave autonomously controls, for example, to brake the inner front wheel to eliminate the understeer, however, the master may request, to the slave, a control that increases the understeer in consideration of the balance between the control of the slave and controls of the other slaves. In this case, the slave operates according to the request of the master and causes to destabilize vehicular running condition without eliminating the understeer. As described above, conventional master-slave control methods have the problem that a slave operates according to the request of a master regardless of vehicular running condition. Unexamined Japanese Patent Publication No. 2005-112007 does not mention this problem.